Electromagnetically-operated apparatus.



R. E. HELLMUND.

ELEOTROMAGNETIOALLY OPERATED APPARATUS.

APPLICATION FILED APR.4,19OG.

928,516.' I Patented July 20, 1909.

Big. 1.

WITNESSES: INVENTOR.

% W A v fiudoZfEEZZmund A ITORNEY a no. 928,518.

UNITED STATES.

PATENT OFFICE.

RUDOLF E. HELLMUND, or HINSDALE, ILLINOIS, ,ASSI'GNOR, BY MESNE ASSIGNMENTS, T

WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, OF EAST PITTSBURG, PENN- SYLVANIA, A ooRPoaA'TmNoF PENNSYLVANIA.

'ELECTBOIAGNETICALLY-OPERATED APPARATUS;

.post ofiice address,of Box130, in Hinsda-le,

county of Dupa'ge, in the State of Illinois,

. have invented Iangrovements in Electromagnetically-Opera Apparatus, of which the following is a, s

ification.

The object o my invention is to provide an electro-magnet which will effectually prevent the generation of more lines of magnetic force than'are necessary to operate the armature of the magnet at anytime during its motion and which, at the same time, is s'imple'in its construction and is capable of.

exerting-aforce of considerable magnitude. All armatures for electro-magnets have a certain definite ma 'etic pull exerted upon them during their rst unit of movement in accordance with a' certain proportionate number of magnetic lines of force passing through the lron of the armature, the amount of pull and the number of lines increasing rapidly as the armature comes nearer to the operating magnet and thus tending to accelerate the motion of the armature. I I

lAn armature that is to overcome any working resistance or element of retardation should, at no time, be attracted by a force greater than thatwhich is necessaryto move it during its initial movement, if undue increase of the magnetic lines of force is to be prevented. If the attracting force is allowed toincrease, as is now the practice, when the circuit is broken, a' self-induction will be set up in the magnet which will be proportionate to the number of lines of force which disappear atthe time of breaking the circuit.

With m allow the ines of force to unduly increase as the armature advances and, consequently, upon breaking the circuit connection, there are fewer lines of force to disappear and thus produce self-inductive action; hence, I am enabled to use coils of greater numbers of turns, which means smaller parts, and also to-increase the Safety of the installation by lessening the liability to arcing when breaking the circuit, and, at the same time,

' flpeciflcationot Letters radiant: application filed A n 4, 1900. Serial No. 309,932.

improved apparatus, I do not Patented July 20, 1909.

I aiding in securing a constant magnetic The device oi my invention may be used with one or more; armatures to operate clutches, circuit-breakers, switches or any armature-operated electrical apparatus. In

a co-pending application, I have shown the armature as applied to a circuit-breaker, but I ha've'not claimed it broadly therein. In this application I have shown a single armature as applied to a switch for operating an eleetriealapparatus from a distance.

=F0r cases where a uniform pull has been required, structures have been" devised, which were adapted 'toreduce the acceleration of theflux, some of which'were, however, complicated and expensive in their construction and others were not practical, in cases where In the accompanying drawin s, Figure l is a side elevationof an electrics ly-operated switch With my improved armature at. tached; Fig. 2 is an end view,,and Fig. 3 is a plan view of the same; Fig. 4 shows the armature and the poles of the magnet of Figs. 1, ,2 and 3, butwith the armature moved through an angle of 90.

In Figs. 1, 2 and 3, A is'a base-plate on which two contact clips 0 c are mounted for making circuit connection with thedevice to receive current.- C is the coil of the magnet M for receiving current from the terminals The oles p, p have concentric ,faces betweenw ich an S-shaped armature S is adapted to rotate, a radial arm a be-' ing mounted on the armature shaft to carr a weight W. A contact blade 6 on the sha t is adapted to make contact, under ma etic influence, with the clips 0, 0' and to reak contact, when under the influence of the weight W only. The S-shaped armature has a; toe Z and a heel n the toe being at a greater distance from the shaft than the heel n, so that, when the armature is revolved 90 from the position shown in Fig. 1, to the position shown in Fig. 4, there will be an airgap between the poles of increasing width from the toe to the heel. As the armature rotates, more iron is inserted into the field which tends to increase the magnetic pull and to accelerate the motion, but

the weight develops an increased moment of a considerable magnetic pull was required.

retardation as it is raised. The air-gap produced by the eccentricity of the armature face is just sufficient to cause an increased number of lines of force, in each successive unit of movement, to so lag behind the increase which would occur in a concentric armature, .thatthe increased lines shall develop in that number and power which, in addition to the linesdeveloped in the previous units of movement, will just overcome the increased moment of retardation.

I am aware that it is not broadly new to provide, in an elect-ro-magnet, means for reducing the acceleration of the flux.

' I claim as my invention:

1. The combination with an electro-magnet having opposing curved pole faces, of a rotatable armature oh S-shape the outer faces ofwhich are eccentric to the pole faces and the toes of which are nearer there to than the heels.

2. Electrical apparatus having a magnet and an S-shaped armature having aneccentrio facedesigned to face the pole faces of said magnet, the eccentricity of the face of the armature being such that the toe of the 8 shall be nearer to-the' pole than the heel, substantially as described. Z

3. The combination with an electro-ma net having curved pole faces, of a rotatab e jecting arms the outer faces of which are eccentric to the ,polefaces, and the'free ends of which are nearer to said pole faces than the body portions. I e a r b a The combinationwith an. electr c-magnet having opposing curvedpolefaces, ofan armature of S'shape the, outer faces a of which are separated from the magnet pole faces by air-gapsthat gradually increase in width from the toes to the heels.

6. Electrical apparatus having a magnet and an S-shaped armature havin an eccentric face designed to face the pole faces of said magnet, the eccentricity of the arma-' ture faces being such that the toes of the 8 shall be nearer to the pole than the heels,

in combination with means of; retardation that increases in moment as the armature.

rotates.- H I RUDOLF E;

Witnesses HJALMAR HER'rz, CARL STUEVE. 

